Electrical devices such as electric vehicles and electrically powered equipment of various types are becoming more important in many applications. Such devices relevant to the present disclosure typically incorporate a relatively large battery pack and a load such as a drive system. An example of such an electrical device is an electric car. An electric car typically includes a relatively large battery or battery pack typically formed of a large plurality of individual battery cells. The battery may be charged by equipment in the car or by off-board equipment and discharges normally by providing power to the drive system and other systems associated with the car. High power levels in excess of 40 KW (and up to and exceeding 150 KW) are often used in such applications, accordingly, safety and reliability are important issues.
Typically the battery and drive systems of electric vehicles are coupled with a functional high-voltage wiring harness capable of transferring tens or hundreds of kilowatts of electrical power between the battery pack and the drive system. Modern electric vehicles incorporate regenerative braking systems and so this power may travel in either direction (to or from the battery) at any given moment.
The high-voltage wiring harness is typically comprised of one or more of the following components: wire or cable; connectors or couplings (having mechanical, soldered or crimped joints); cell-to-cell connections; fuses and their holders; and contactors. Any fault in any of these components can cause a relatively large resistance in an otherwise low resistance path which, due to the large currents and voltage present, can result in large and undesirable amounts of heat being generated within a small area of the electrical vehicle. Early detection and response to such a fault would be highly desirable.